With increasingly serious energy and environmental problems, development of new energy saving products is critical to the modern society. Vacuum glass has excellent thermal insulation properties and attracted wide spread attention. The preparation of vacuum glass involves vacuum technology, materials science, machinery, automation technology and other fileds. The key technology of vacuum glass is to prepare the sealing glass which have low melting point and matched the coefficient of expansion. V2O5-P2O5-TeO2 (VPT) lead-free sealing glass was prepared by melting method. The composition of the glass structure, transition temperature and coefficient of thermal expansion had been studied. The glass transition temperature of is 350°C. The expansion coefficient of VPT glass is (82~89)×10-7, which matches with substrate glass. X-ray diffraction and ultra-depth three-dimensional microscope is utilized to investigate the sinterin, crystallization and microstructure of the VPT low-melting glass. The glass slurry was synthesized and modulated to obtain optimum viscosity for low temperature sealing of vacuum glass during the experimental.